cells Review Grb7, a Critical Mediator of EGFR/ErbB Signaling, in Cancer Development and as a Potential Therapeutic Target 1, 1,2, 1,3, Pei-Yu Chu y , Yu-Ling Tai y and Tang-Long Shen * 1 Department of Plant Pathology and Microbiology, National Taiwan University, Taipei 10617, Taiwan;
[email protected] (P.-Y.C.);
[email protected] (Y.-L.T.) 2 Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA 3 Center for Biotechnology, National Taiwan University, Taipei 10617, Taiwan * Correspondence:
[email protected]; Tel.: +886-2-3366-4998 These authors contributed equally to this work. y Received: 30 March 2019; Accepted: 9 May 2019; Published: 10 May 2019 Abstract: The partner of activated epidermal growth factor receptor (EGFR), growth factor receptor bound protein-7 (Grb7), a functionally multidomain adaptor protein, has been demonstrated to be a pivotal regulator for varied physiological and pathological processes by interacting with phospho-tyrosine-related signaling molecules to affect the transmission through a number of signaling pathways. In particular, critical roles of Grb7 in erythroblastic leukemia viral oncogene homolog (ERBB) family-mediated cancer development and malignancy have been intensively evaluated. The overexpression of Grb7 or the coamplification/cooverexpression of Grb7 and members of the ERBB family play essential roles in advanced human cancers and are associated with decreased survival and recurrence of cancers, emphasizing Grb70s value as a prognostic marker and a therapeutic target. Peptide inhibitors of Grb7 are being tested in preclinical trials for their possible therapeutic effects. Here, we review the molecular, functional, and clinical aspects of Grb7 in ERBB family-mediated cancer development and malignancy with the aim to reveal alternative and effective therapeutic strategies.